3D Mesh Simplification Preserving Structural Edges

Solution Overview

Problem

Existing mesh simplification techniques often result in the loss of shape details for high-level structures like skylines and building outlines in three-dimensional models, leading to a compromised visual quality during the reduction of polygon meshes for storage and processing efficiency.

Innovation Solution

The method involves identifying structural edges in a three-dimensional polygon mesh, constructing sharp edges at these intersections, and using these edges as criteria for mesh simplification while determining edge collapse errors based on their location, ensuring that critical features are preserved during the simplification process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If typical mesh simplification techniques are used to reduce the size of dense mesh, then the storage and processing requirements are reduced, but the shape of high-level structures (skylines, building outlines, bridges) is lost

Engineering Contradiction:

Improvenumber of vertices and edgesVSAvoidshape of high-level structures

Core Design Contradiction:

Quantity of substanceVSShape

Solution Approach 1:

The patent applies local quality by treating different regions of the mesh differently during simplification. Structural edges identified through plane detection are preserved with high fidelity, while non-structural regions are simplified more aggressively. This is achieved by computing error metrics that are sensitive to deviations from structural edges, ensuring that high-level structures maintain their original shape while other areas are reduced in complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent performs preliminary action by pre-identifying structural edges through plane detection and normal analysis before the actual simplification process begins. By detecting planes and computing their intersections to identify structural edges in advance, the method establishes a framework that guides subsequent simplification operations to preserve these critical features while reducing overall mesh complexity.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the polygon mesh is reduced to fewer vertices and edges for storage efficiency, then the processing time is reduced, but the visual quality of the three-dimensional model deteriorates

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidvisual quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by treating different regions of the mesh differently during simplification. Structural edges identified through plane detection are preserved with high fidelity, while non-structural regions are simplified more aggressively. This is achieved by computing error metrics that are sensitive to deviations from structural edges, ensuring that high-level structures maintain their original shape while other areas are reduced in complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements feedback by using error metrics that continuously evaluate the impact of simplification operations on structural edges. The error computation considers the distance to structural edges and the orientation of faces relative to detected planes, providing feedback that guides the selection and execution of simplification operations. This feedback mechanism ensures that visual quality is maintained by preventing operations that would significantly degrade the representation of high-level structures.

Inventive Principle:

Principle #23Feedback

3Quantity of substance

If aggressive mesh simplification is applied to reduce file size, then the storage requirements are reduced, but the important structural features (building outlines, skylines) are compromised

Engineering Contradiction:

Improvemesh data sizeVSAvoidstructural feature information

Core Design Contradiction:

Quantity of substanceVSLoss of information

Solution Approach 1:

The patent performs preliminary action by pre-identifying structural edges through plane detection and normal analysis before the actual simplification process begins. By detecting planes and computing their intersections to identify structural edges in advance, the method establishes a framework that guides subsequent simplification operations to preserve these critical features while reducing overall mesh complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using error metrics that continuously evaluate the impact of simplification operations on structural edges. The error computation considers the distance to structural edges and the orientation of faces relative to detected planes, providing feedback that guides the selection and execution of simplification operations. This feedback mechanism ensures that visual quality is maintained by preventing operations that would significantly degrade the representation of high-level structures.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9373192B2Shape preserving mesh simplification

Publication Date: 2016.06.21 GOOGLE LLC

AI summary

Systems and methods for simplifying a three-dimensional mesh providing a three-dimensional model, such as a three-dimensional model of a cityscape, are provided. In particular, mesh simplification techniques can preserve important structural shapes in the original three-dimensional mesh. Important features in a representation of a city scene or other scene can be represented by structural edges (e.g. building outlines, bridges, curved structures such as curved highway overpasses, etc.). These structural edges can be detected and a representation of the structural edges can be constructed in the mesh. The mesh can then be simplified using the structural edges as high-level simplification criterion such that the structural edges are preserved during simplification.